Thioamide-Directed Cobalt(III)-Catalyzed Selective Amidation of C(sp 3 )-H Bonds.

Autor: Tan PW; Organic Chemistry, Institute of Chemical and Engineering Sciences, 8 Biomedical Grove, Neuros, #07-01, Singapore, 138665, Singapore., Mak AM; Institute of High Performance Computing, 1 Fusionopolis Way #16-16, Singapore, 138632, Singapore., Sullivan MB; Institute of High Performance Computing, 1 Fusionopolis Way #16-16, Singapore, 138632, Singapore., Dixon DJ; Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, UK., Seayad J; Organic Chemistry, Institute of Chemical and Engineering Sciences, 8 Biomedical Grove, Neuros, #07-01, Singapore, 138665, Singapore.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2017 Dec 22; Vol. 56 (52), pp. 16550-16554. Date of Electronic Publication: 2017 Nov 30.
DOI: 10.1002/anie.201709273
Abstrakt: A mild, oxidant-free, and selective Cp*Co III -catalyzed amidation of thioamides with robust dioxazolone amidating agents via C(sp 3 )-H bond activation to generate the desired amidated products is reported. The method is efficient and allows for the C-H amidation of a wide range of functionalized thioamides with aryl-, heteroaryl-, and alkyl-substituted dioxazolones under the Cp*Co III -catalyzed conditions. The observed regioselectivity towards primary C(sp 3 )-H activation is supported by computational studies and the cyclometalation is proposed to proceed by means of an external carboxylate-assisted concerted metalation/deprotonation mechanism. The reported method is a rare example of the use of a directing group other than the commonly used pyridine and quinolone classes for Cp*Co III -catalyzed C(sp 3 )-H functionalization and the first to exploit thioamides.
(© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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